450. A simple sentence is a sentence which makes a single assertion, question or command.

The simple sentence contains only words and phrases.

451. A complex sentence is one which contains a principal statement and one or more modifying statements.

The statements made in addition to the principal statement are made in dependent clauses. The complex sentence has only one main clause and one or more dependent clauses.

452. A compound sentence is one which contains two or more independent clauses.

These compound sentences may contain any number of dependent clauses but they must always have at least two independent or principal clauses. These principal clauses are always connected by co-ordinate conjunctions, for the principal clauses in a compound sentence are always of equal rank or order.

Exercise 1

Review the lesson on co-ordinate conjunctions and notice which conjunctions are used to unite principal clauses into single sentences. Use these co-ordinate conjunctions to unite the following pairs of simple sentences into compound sentences. For example:

The sun rises.The day dawns.
He studies diligently.He learns rapidly.
He came early.He could not stay.
The weather is cold.The plants are not growing.
The men work.The boys play.
The day is cold.The wind is blowing.